Recombinant collagenase type I from clostridium histolyticum and its use for isolating cells and groups of cells

ABSTRACT

A polypeptide with the properties of collagenase class I from Clostridium histolyticum (CHC I) and the amino acid sequence SEQ ID NO:2 which is optionally N-terminally extended by one or several amino acids of the sequence SEQ ID NO:3 is advantageously suitable for the isolation of cells from mammalian tissue and human tissue.

The present invention claims priority to the following applications: 1) EP 96 118 490.0, filed Nov. 19, 1996; 2) EP 97 101 085.5, filed Jan. 24, 1997; and 3) PCT/EP97/06002, filed Oct. 30, 1997.

The invention concerns a recombinant collagenase type I (CHC I) from Clostridium histolyticum and its use for isolating cells and groups of cells.

Bacterial collagenases, e.g. from Clostridium histolyticum, are used to digest tissues and to isolate individual cells or groups of cells (e.g. islets) (islets: Sutton et al., Transplantation 42 (1986) 689-691; liver: Quibel et al., Anal. Biochem. 154 (1986) 26-28; bones: Hefley et al., J. Bone Mineral Res. 2 (1987) 505-516; umbilical cord: Holzinger et al., Immunol. Lett. 35 (1993) 109-118). Two different collagenase types are known from Clostridium histolyticum (M. F. French et al., J. Protein Chemistry 11 (1992) 83-97). The isolation and purification of collagenases from Clostridium histolyticum is described for example in E. L. Angleton and H. E. van Wart, Biochemistry 27 (1988) 7413-7418 and 7406-7412.

Collagenases I were isolated and described by M. D. Bond and H. E. Van Wart, Biochemistry 23 (1984) 3077-3085 and 3085-3091 as well as by H. E. Van Wart, Biochemistry 24 (1985) 6520-6526. Accordingly the collagenases a (MW 68 kD), β (MW 115 kD), γ (MW 79 kD) and η (MW 130 kD) are known as collagenases I. Collagenases I and collagenases II differ in their relative activity towards collagen and towards synthetic peptides. Collagenases I have higher activities towards collagen and gelatin and lower activities towards the short-chained peptides than collagenase II (Bond and Wart, Biochemistry 23 (1984) 3085-3091).

Further collagenases are described in the U.S. Pat. Nos. 5,418,157 and 5,177,011 with a molecular weight of 68 kD. WO 91/14447 also describes a collagenase with a molecular weight of 68 kD. A recombinant collagenase with a molecular weight of ca. 110 kD is described in WO 94/00580 and a sequence is stated for it. Nothing is stated in WO 94/00580 about its specificity and in particular whether it is a collagenase I or II. In addition to a collagenase with a molecular weight of 110 kD, a 125 kD collagenase is additionally mentioned which it is claimed can also be produced recombinantly. However, WO 94/00580 does not give more details about this collagenase.

The object of the present invention is to provide a highly active stable collagenase class I from Clostridium histolyticum (CHC I).

The object is achieved by a process for the production of a polypeptide which has the properties of a CHC I from Clostridium histolyticum, has a given amino acid composition and is obtainable by expression of an exogenous nucleic acid in prokaryotic or eukaryotic host cells and isolation of the desired polypeptide wherein the nucleic acid codes for a polypeptide having sequence ID NO:2 or a polypeptide which is extended N-terminally by one or several amino acids having the sequence ID NO:3.

It has surprisingly turned out that a CHC I according to the invention has a high collagenase class I activity and is very stable. A CHC I having the amino acid sequence SEQ ID NO:2 and a CHC I which is N-terminally extended by one or several amino acids having SEQ ID NO:3 are particularly preferred.

The CHC I according to the invention is a highly pure enzyme which can be produced in large amounts. The CHC I according to the invention is not contaminated by other clostridial enzymes and is free of toxins.

The CHC I according to the invention is especially suitable for isolating cells from tissues of mammals, preferably from human tissue, for an application in cell therapy (transplantation, immunotherapy) and for an application in gene therapy in tissues: e.g. pancreas, liver, bone, cartilage, skin, brain and nerve tissue, fat, muscle, heart, endothelium, kidney, solid tumours and for the purification of ulcers.

In addition this highly pure enzyme (preferably in a mixture with other-highly pure enzymes (such as collagenase II and neutral protease)) is particularly suitable for the isolation of cells whose surface molecules/markers (antigens) should not be changed. Preferred applications of this are for example the dissociation of solid tumours of all types in vitro (e.g. colon, breast etc.) for adoptive immunotherapy and for general diagnosis such as e.g. to detect rare cells. from tissues and solid tumours by means of specific surface markers/molecules.

The production of the recombinant CHC I can be carried out according to methods familiar to a person skilled in the art.

For this a DNA molecule is firstly produced which is capable of producing a protein which has the activity of CHC I. The DNA sequence is cloned into a vector which can be transferred into a host cell and can be replicated there. Such a vector contains promoter/operator elements which are necessary to express the DNA sequences in addition to the CHC I sequence. This vector which contains the CHC I sequence and the promoter/operator elements is transferred into a host cell which is able to express the DNA of CHC I. The host cell is cultured under conditions which are suitable for the amplification of the vector and CHC I is isolated. In this process suitable measures ensure that the protein can adopt an active tertiary structure in which it exhibits CHC I properties.

The nucleic acid sequence and protein sequence can be modified to the usual extent. Such modifications are for example:

Modification of the nucleic acid in order to introduce various recognition sequences of restriction enzymes to facilitate the steps of ligation, cloning and mutagenesis.

Modification of the nucleic acid to incorporate preferred codons for the host cell.

Extension of the nucleic acid by additional operator elements in order to optimize the expression in the host cell.

Substitution or deletion of amino acids while retaining the basicity and the spatial structure of CHC I. It is advantageous to preserve 85% or more and preferably 90% or more of the original amino acid sequence.

A further subject matter of the invention is a polypeptide with the properties of a collagenase class I from Clostridium histolyticum with the amino acid sequence according to SEQ ID NO:2 or a polypeptide extended N-terminally by one or several amino acids of SEQ ID NO:3. A further subject matter of the invention is a nucleic acid coding for such a protein.

The protein is preferably produced recombinantly in microorganisms, in particular in prokaryotes and in this case in E. coli.

Suitable expression vectors must contain a promoter which allows expression of the protein in the host organism. Such promoters are known to a person skilled in the art and are for example the lac promoter (Chang et al., Nature 198 (1977) 1056), trp promoter (Goeddel et al., Nuc. Acids Res. 8 (1980) 4057), λ_(PL) promoter (Shimatake et al., Nature 292 (1981) 128) and T5 promoter (U.S. Pat. No. 4,689,406). Synthetic promoters are also suitable such as for example the tac promoter (U.S. Pat. No. 4,551,433). Coupled promoter systems are also suitable such as the T7-RNA polymerase/promoter system (Studier et al., J. Mol. Biol. 189 (1986) 113). Hybrid promoters composed of a bacteriophage promoter and the operator region of the microorganism (EP-A 0 267 851) are equally suitable. An effective ribosome binding site is necessary in addition to the promoter. In the case of E. coli this ribosome binding site is denoted the Shine-Dalgarno (SD) sequence (Sambrook et al., “Expression of cloned genes in E. coli” in Molecular Cloning: A laboratory manual (1989) Cold Spring Harbor Laboratory Press, New York, USA).

In order to improve the expression it is possible to express the protein as a fusion protein. In this case a DNA sequence which codes for the N-terminal part of an endogenous bacterial protein or for another stable protein is usually fused to the 5′ end of the DNA coding for the CHC I. Examples of this are for example lacZ (Phillips and Silhavy, Nature 344 (1990) 882-884), trpE (Yansura, Meth. Enzymol. 185 (1990) 161-166).

After expression of the vector, preferably a biologically functional plasmid or a viral vector, the fusion proteins are preferably cleaved with enzymes (e.g. factor Xa) (Nagai et al., Nature 309 (1984) 810). Other examples of cleavage sites are the IgA protease cleavage site (WO 91/11520, EP-A 0 495 398) and the ubiquitin cleavage site (Miller et al., Bio/Technology 7 (1989) 698).

The proteins expressed in this manner in bacteria are isolated in the usual way by lysing the bacteria and protein isolation.

In a further embodiment it is possible to secrete the proteins as active proteins from the microorganisms. For this a fusion product is preferably used which is composed of a signal sequence which is suitable for the secretion of proteins in the host organisms used and the nucleic acid which codes for the protein. In this process the protein is either secreted into the medium (in the case of gram-positive bacteria) or into the periplasmic space (in the case of gram-negative bacteria). It is expedient to place a cleavage site between the signal sequence and the sequence coding for CHC I which enables cleavage of the protein either during processing or in an additional step. Such signal sequences are derived for example from ompA (Ghrayeb et al. EMBO J. 3 (1984) 2437) or phoA (Oka et al., Proc. Natl. Acad. Sci. USA 82 (1985) 7212).

The vectors in addition also contain terminators. Terminators are DNA sequences which signal the end of a transcription process. They are usually characterized by two structural features: an inverse repetitive G/C-rich region which can intramolecularly form a double helix and a number of U(or T) residues. Examples are the main terminator in the DNA of the phage fd (Beck and Zink, Gene 16 (1981) 35-58) and rrnB (Brosius et al., J. Mol. Biol. 148 (1981) 107-127).

In addition the expression vectors usually contain a selectable marker in order to select the transformed cells. Such selectable markers are for example the resistance genes for ampicillin, chloroamphenicol, erythromycin, kanamycin, neomycin and tetracyclin (Davies et al., Ann. Rev. Microbiol. 32 (1978) 469). Selectable markers which are also suitable are the genes for substances that are essential for the biosynthesis of substances necessary for the cell such as e.g. histidine, tryptophan and leucine.

Numerous suitable bacterial vectors are known. Vectors have for example been described for the following bacteria: Bacillus subtilis (Palva et al., Proc. Natl. Acad. Sci. USA 79 (1982) 5582), E. coli (Aman et al., Gene 40 (1985) 183; Studier et al., J. Mol. Biol. 189 (1986) 113), Streptococcus cremoris (Powell et al., Appl. Environ. Microbiol. 54 (1988) 655), Streptococcus lividans and Streptomyces lividans (U.S. Pat. No. 4,747,056).

Further genetic engineering methods for the construction and expression of suitable vectors are described in J. Sambrook et al., Molecular Cloning: A laboratory manual (1989), Cold Spring Harbor Laboratory Press, New York, N.Y.

Apart from in prokaryotic microorganisms, recombinant CHC I can also be expressed in eukaryotes (such as for example CHO cells, yeast or insect cells). The yeast system or insect cells is preferred as the eukaryotic expression system. Expression in yeast can be achieved by means of three types of yeast vectors (integrating YIp (yeast integrating plasmids) vectors, replicating YRp (yeast replicon plasmids) vectors and episomal YEp (yeast episomal plasmids) vectors. More details of this are for example described in S. M. Kingsman et al., Tibtech 5 (1987) 53-57).

The invention in addition concerns a process for disintegrating cell tissue and releasing cells or groups of cells contained therein by incubating the cell tissue with a collagenase class I from Clostridium histolyticum until the cells or groups of cells have been released to the desired extent and separating the cells or groups of cells from the cell tissue fractions. The separation of the cells or groups of cells from the cell tissue fractions is preferably carried out by centrifugation using a density gradient.

Cells or groups of cells are usually isolated from tissues (e.g. pancreas, liver, skin, endothelium, umbilical cord, bone, tumour tissue) by incubating organs, parts of organs or tissues with enzymes which dissolve the surrounding extracellular connective tissue matrix (islets: Sutton et al., Transplantation 42 (1986) 689-691; liver: Quibel et al., Anal. Biochem. 154 (1986) 26-28; bone: Hefley et al., J. Bone Mineral Res. 2 (1987) 505-516); umbilical cord: Holzinger et al., Immunol. Lett. 35 (1993) 109-118). Tumour cells isolated in this manner can be used advantageously for tumour vaccination and/or adoptive immunotherapy. Tissue disintegration can also be carried out by perfusing the entire organ (Ricordi et al., Diabetes 37 (1988) 413-420) with an enzyme solution. Important factors in this process, in addition to the composition of the enzyme mixture, are the duration, the pH value and the temperature of the digestion as well as the mechanical action e.g. by shaking and addition of metal balls. Since extracellular connective tissue matrix often has a high proportion of collagen, collagenases play a special role (Wolters, Hormone and Metabolic Research 26 (1994), 80).

The process according to the invention is preferably used to isolate islets or islet cells from pancreatic tissue.

In addition, the addition of further enzymes such as proteinases (e.g. neutral protease, cf. example 5 or other metalloproteases; serine proteases such as trpysin, chymotrypsin, plasmin etc.; cysteine proteases; aspartate proteases), elastases, hyaluronidase, lipases or other collagenases may be advantageous for the quality of the digestion.

The invention is further elucidated by the following examples, the figure and the sequence protocol.

The sequence protocols denote:

SEQ ID NO: 1: DNA fragment of CHC I

SEQ ID NO: 2: derived protein fragment

SEQ ID NO: 3: N-terminal extension

SEQ ID NO: 4: 4-24: primers and peptide fragments

FIG. 1 shows the expression vector p-Lac-F-Col1-3.

EXAMPLE 1 Purification of the Collagenase Class I (CHC I)

1 g collagenase P (from Clostridium histolyticum, Boehringer Mannheim GmbH, cat. No. 1 213 857) was dissolved in 20 ml H₂O (milli Q quality) and particulate components were removed by centrifugation. After a 60% ammonium sulfate precipitation, the precipitate was taken up in 9.5 ml H₂O and dialysed overnight at 4° C. against 10 mM Tris-HCl, pH 7.5.

The dialysate was applied at room temperature to a Zn-chelate Sepharose column (column volume CV=50 ml, 2 cm diameter). Subsequently the column was washed with 10 mM Tris HCl, pH 7.5.

The eluant peak which contains the CHC I fractions was further separated on a Mono Q column (Pharmacia) in 10 mM/l Tris HCl, pH 7.5 using a linear gradient up to 10 mM/l Tris, pH 7.5, 0.3 M/l NaCl. The peak containing the CHC I activity (activity determined as azocoll activity according to Chavira et al., Anal. Biochem. 136 (1984) 446-450) is further purified by means of reversed phase HPLC (mobile solvent A: 0.12% TFA (trifluoroacetic acid/H₂O, 25% acetonitrile, step gradient up to 50% acetonitrile within 5 min and up to 70% acetonitrile within 15 min). The fraction of the second gradient stage containing the main peak is evaporated to dryness and, after carboxymethylation, subjected to digestion with endoproteinase LysC. The peptides were also separated by reversed phase HPLC (Vydac C4) with a gradient of 5-45% acetonitrile/0.12% TFA within 105 min. The peptides were collected, evaporated to dryness and sequenced.

EXAMPLE 2 Cloning of the Collagenase Class I from Clostridium Histolyticum

2.1 A 1.4 kB segment of the CHC I gene that was derived from peptide sequences that had been obtained by digestion of purified collagenase I from Clostridium histolyticum according to example 1 was isolated with the aid of a PCR reaction. This segment or fragments thereof were used to prepare a DNA probe which can for example be labelled with Dig. Such a probe is used to screen gene banks in order to isolate the remainder of the CHC I gene.

Peptide Sequences:

Coll-I-2Q: F N S P E E Y (SEQ ID NO:4)

Coll-I-72: E D G D V T I (SEQ ID NO:5)

Primers derived therefrom:

Coll-1-2QF: 5′ tty aay wsn ccn gar gar tay (SEQ ID NO:6)

Coll-1-2QR: 5′ rta ytc ytc ngg nsw rtt raa (SEQ ID NO:7)

Coll-1-72F: 5′ gar gay ggn gay gtn acn att (SEQ ID NO:8)

Coll-1-72R: 5′ dat ngt nac rtc ncc rtc ytc (SEQ ID NO:9)

Four primers were designed and used in two different PCR reactions (primer combinations 2QF/72R and 2QR/72F). Only the combination 2QF with 72R yielded a PCR product (length 1.4 kB) which corresponded to the sequence from position 2418 to 3806 of the total sequence shown in SEQ ID NO:1.

The identity of this piece and the reading frame on it were confirmed by recovery of additional peptide sequences of collagenase I from Clostridium histolyticum:

peptide 1-23: DWDEMSK (SEQ ID NO:10)

peptide 1-33: VTGPSTGAVGRNIEFSGK (SEQ ID NO:11)

peptide 1-40: NTEYQNHIQELVDK (SEQ ID NO:12)

b 2.2 Gene Bank Screening

It was possible to isolate a DNA fragment of 5.4 kB in length which contained the entire 1.4 kB probe from a gene bank which was prepared from Stu I/HindII cleaved genomic DNA of Clostridium histolyticum with the aid of a digoxigenin-labelled fragment (derived from the above 1.4 kB fragment). DNA sequencing from the ends of the known 1.4 kB sequence enabled the CHC I sequence to be completed at the 3′ end and extended at the 5′ end up to a Stu I cleavage site.

The sequence at the 3′ end corresponds to position 3807 to 4358 of the total sequence shown in SEQ ID NO:1.

The sequence of a further peptide of the wild-type enzyme was found in this sequence section:

peptide 1-67: EDGDVTIELPYSGSSNFTWLVY (SEQ ID NO:13)

A large part of this peptide overlaps with peptide 1-72 (SEQ ID NO:5) but it contains 4 additional amino acids which cannot yet be found on the original 1.4 kB DNA fragment.

The sequence at the 5′ end corresponds to position 1969 to 2417 of the total sequence shown. in SEQ ID NO:1.

It was also possible to identify a DNA fragment of 4.6 kB from a Bgl II gene bank using the labelled 1.4 kB probe. This fragment proved to be not clonable as a whole but it was possible to sequence it from the Stu I site onwards and yielded further sequence information about the 5′ region.

The sequence found corresponds to position 1630 to 1974 of the total sequence shown in SEQ ID NO:1.

It was possible to confirm that this sequence belongs to the collagenase I gene by discovery of a further peptide:

Peptide 1-42: QFRENLNQYAPDYVK (SEQ ID NO:14)

2.3 Inverse PCR

In an experiment aimed at gaining information about the 5′ region of the gene by means of an inverse PCR, genomic DNA from Clostridium histolyticum cleaved with StuI was separated in an agarose gel, the 1.9-2.7 kB region was isolated (cut out of the gel), religated and amplified by inverse PCR:

Primers used:

449-coll1: 5′-aga caa tgc ctt ggt atg g (SEQ ID NO:15)

453-coll1-R: 5′-gtg aaa gtt tct ata ccc ttc (SEQ ID NO:16).

A fragment of 1.85 kB was obtained which could not be cloned as a whole but it was possible to determine a partial sequence.

This is position 1384 to position 1570 of the total sequence shown in SEQ ID NO:1.

This sequence is in the start region and immediately upstream of the previously described sequence for the collagenase I gene from Clostridium histolyticum.

2.4 Cloning of the 5′ Region of the Collagenase I Gene from Clostridium Histolyticum

Genomic DNA from Clostridium histolyticum was digested with HindIII/StuI and separated in an agarose gel. The region between 1.7 and 2.2 kB was cut out (expected fragment in Southern blot is at 1.9 kB). The DNA was isolated from the gel by conventional methods (QiaEx) and cloned into pUC19 by means of HindIII/HindII.

2.5 Gene Bank Screening

The HindIII/StuI gene bank was screened with a ca. 400 bp long Dig-labelled probe. The sequence of the probe corresponds to position 1453 to 1852 of the total sequence shown in SEQ ID NO:1.

The probe was prepared with the aid of two primers:

464-coll1: 5′-gta cag gtt ctc aaa agt tc (SEQ ID NO:17)

448-coll1-R:5′-gtt cct tta acg taa tca gg (SEQ ID NO:18)

Among ca. 2200 screened clones, there were 14 with a positive signal, plasmid minipreps were carried out on these using conventional methods, the best 4 clones all contained the same insert which corresponds to position 1-1971 of the total sequence shown in SEQ ID NO:1.

A total length for the CHC I gene and its upstream region of ca. 4.4 kB results with this sequence. The complete sequence is shown in SEQ ID NO:1.

A large open reading frame is positioned on this sequence which in the 3′ region runs into the already described part of the collagenase I. Potential starting points for translation are located at position 1002 (ATG), 1029 (ATG), 1110 (ATG) as well as 1176 (GTG) and 1254 (GTG).

2.6 Constructs Extended in the 5′ Region

An N-terminus of a possible mature form of the collagenase (IANTNSEK - SEQ ID NO:19) determined by protein sequencing is at position 1332 of SEQ ID NO:1. The corresponding polypeptide is shown in SEQ ID NO:2. Since all the translation starting points described above are further in the 5′ direction and lie within the frame, several expression constructs were prepared and their expression properties were examined. It surprisingly turned out that starts at several positions each led to actively expressed enzymes.

Examples of such constructs:

A SmaI or AvaI cleavage site can be introduced 5′ before ATG 1002, 1029, 1110 or GTG 1176 or 1254 by suitable selection of the primers. If a counter primer is used which is located on the far side of the BfrI cleavage site (1965-1970), then all others can be prepared from a pUCBM20 expression vector by exchange via SmaI or AvaI and BfrI cleavage.

start at 1002: MTMITNSRA MKKNILKIL . . . (SEQ ID NO:20)

start at 1029: MTMITNSRA MDSYSKESK . . . (SEQ ID NO:21)

start at 1176: MTMITNSRA MKNIEEAKV . . . (SEQ ID NO:22) The underlined sequence is in each case a fusion part from pUCBM20 resulting from the construction.

It is known that GTG sequences may also come into consideration as a start position. A particularly preferred start is at GTG 1176 which can be converted into an ATG by selection of a suitable primer:

primer 472-Col1: 5′-ttc cca att gcc cgg gct atg aaa aat ata gaa gag gca aag (SEQ ID NO:23)

This leads to the expression vector placF-col1-3 (FIG. 1).

2.7 Further Expression Possibilities

The expression constructs described previously use the lac promoter and the homologous signal peptide. Other promoters can be used equally well instead of these such as mgl (EP-B 0 285 152) or tac (EP-B 0 067 540).

The signal peptide can also be replaced by others e.g. the mgl signal peptide. Such a heterologous signal peptide should preferably be inserted directly in front of the mature 5′ end of the collagenase gene. However, also in this case it turned out that several positions are conceivable. Hence an mgl signal in front of the peptide sequence IANTNSEK (SE ID NO:19) and in front of AYLTMNTS (SEQ ID NO:24) leads to active expression of CHC I. The fusion part from pUCBM20 caused by the construction is also not necessary. Expression still takes place when the fusion part is shortened or entirely removed. It is also possible to completely remove the signal and cytoplasmically express CHC I.

2.8 Strains

Known E. coli K12 strains such as e.g. C600, HB101 and similar ones are preferably used to express CHC I. Other prokaryotic systems and also gram-positive (e.g. bacillus or streptomyces) and expression in eukaryotic cell systems is also conceivable.

2.9 Molecular Weight

purified (wild-type): ca. 115 kDa (after SDS gel electrophoresis)

purified (rec): ca. 115 kDa (after SDS gel electrophoresis)

theoret. (IANTNSEK): 113897

theoret. (AYLTMNTSS): 122547

EXAMPLE 3 Expression of Collagenase Class I

10 1 fermentation of the E. coli expression clone for CHC I and high pressure lysis

Precultures are prepared from type cultures (plate smear, ampoules or paillettes) which are incubated at 30-37° C. while shaking.

The inoculation volume into the next higher dimension is 1-10 vol % in each case. Ampicillin (50-100 mg/l) is added to the preculture and main culture to select against plasmid loss.

Enzymatically digested protein and/or yeast extract as an N- and C-source as well as glycerol and/or glucose as an additional C-source can be used as nutrients. The medium is buffered to pH 7 and metal salts can be added at physiologically tolerated concentrations to stabilize the fermentation process.

The fermentation is carried out as a fed batch with a mixed protein/yeast extract dosage. The growth rate is regulated by the dosage rate and the pH value is controlled by means of glycerol and/or glucose as an acid regulator. The dissolved oxygen partial pressure (pO₂) is maintained at >20% in order to avoid anaerobic conditions by means of the aeration rate, rpm regulation and dosage rate. The fermentation temperature is 25-37° C.

The growth is determined by measuring the optical density at 528 nm. Expression of CHC I is induced by means of IPTG or lactose. After a fermentation period of ca. 30-40 h the biomass is harvested at OD standstill by centrifugation.

The biomass is taken up in a suitable buffer and lysed by a continuous high pressure press at 1000 bar. The suspension obtained in this manner is again centrifuged and the supernatant which contains dissolved CHC I is processed further.

EXAMPLE 4 Islet Isolation from Porcine Pancreas

The pancreas is prepared from a freshly slaughtered pig and cooled in ice-cold HBSS buffer (Gibco) until further processing. A cannula is inserted into the ductus pancreaticus and fastened there, the water-tightness of the pancreas is tested using HBSS buffer. An enzyme solution in HBSS buffer+Ca²⁺which contains purified recombinant collagenase type I alone or in combination with a purified native or recombinant neutral protease and/or collagenase type II from Clostridium histolyticum is injected. The pancreas treated in this way is connected to the perfusion unit that also contains the above-mentioned enzyme solution (discontinuous perfusion). The digestion is carried out between 4° C. and 37° C. during a time period of 5 to 120 minutes. The pump is stopped after the time that is assumed to be optimal and the vessel containing the pancreas is carefully shaken for 3 to 20 minutes by hand. If needed, the prior addition of metal balls additionally facilitates the mechanical dissociation of the tissue and release of the islets from the surrounding exocrine tissue.

The digestion is stopped by addition of ice-cold HBSS/10% FCS (foetal calf serum) and the suspension is filtered through a sieve (mesh size 300 μm) in order to separate coarse particles. The islets present in the filtrate are centrifuged for 10 minutes at 100 g in 250 ml Nalgene round-bottom flasks. The supernatant is decanted and the pellet containing the islets is resuspended in 50 ml FCS.

The islets can be purified further by means of a density gradient made by hand. Firstly 7 ml islet suspension is added to 250 ml Nalgene round-bottom flasks. These are firstly overlayered with 93 ml of a Ficoll® solution (φ=1.077 g/cm³), and then with 50 ml medium (RPMI 1640). These gradients are centrifuged for 10 minutes at 100 g in a swing-out rotor. Fractions of 10 ml are collected, the size, purity and yield of the islets stained with dithiozone is determined microscopically in every fraction or with the aid of image analysis.

List of References

Amann et al., Gene 40 (1985) 183

Angleton, E. L. and Van Wart, H. E., Biochemistry 27 (1988) 7413-7418 and 7406-7412

Beck and Zink, Gene 16 (1981) 35-58 Bond, M. D. and Van Wart, H. E., Biochemistry 23 (1984) 3077-3085

Bond, M. D. and Van Wart, H. E., Biochemistry 23 (1984) 3085-3091

Brosius et al., J.Mol.Biol. 148 (1981) 107-127

Chang et al., Nature 198 (1977) 1056

Davies et al., Ann.Rev.Microbiol. 32 (1978) 469

EP-A 0 267 851

EP-A 0 495 398

French, M. F., et al., J.Protein Chemistry 11 (1992) 83-97

Ghrayeb et al., EMBO J. 3 (1984) 2437

Goeddel et al., Nuc. Acids Res. 8 (1980) 4057

Hefley et al., J.Bone Mineral Res. 2 (1987) 505-516

Holzinger et al., Immunol. Lett. 35 (1993) 109-118

Kingsman, S.M. et al., Tibtech 5 (1987) 53-57

Miller et al., Bio/Technology 7 (1989) 698

Nagai et al., Nature 309 (1984) 810

Oka et al, Proc.Natl.Acad.Sci. USA 82 (1985) 7212

Palva et al., Proc.Natl.Acad.Sci. USA 79 (1982) 5582

Phillips and Silhavy, Nature 344 (1990) 882-884

Powell et al., Appl.Environ.Microbiol. 54 (1988) 655

Quibel et al, Anal.Biochem. 154 (1986) 26-28

Ricordi et al, Diabetes 37 (1988) 413-420

Sambrook et al., “Expression of cloned genes in E. coli” in Molecular Cloning: A laboratory manual (1989) Cold Spring Harbor Laboratory Press, New York, USA

Shimatake et al., Nature 292 (1981) 128

Studier et al., J.Mol.Biol. 189 (1986) 113

Sutton et al., Transplantation 42 (1986) 689-691

U.S. Pat. No. 4,551,433

U.S. Pat. No. 4,689,406

U.S. Pat. No. 4,747,056

U.S. Pat. No. 5,177,011

U.S. Pat. No. 5,418,157

Van Wart, H. E., Biochemistry 24 (1985) 6520-6526

WO 91/11520

WO 91/14447

WO 94/00580

Wolters, Hormone and Metabolic Research 26 (1994) p.80

Yansura, Meth.Enzymol. 185 (1990) 161-166

24 1 4358 DNA Clostridium histolyticum CDS (1332)..(4358) 1 aagcttttat aattctcact atactctcta gatggtataa taagagccca aaatacgaag 60 aatataataa aatataattt aaaaaggatg atttcaatgc gaaaaagagt ttttttgaat 120 atatttttta ttttatgttc ctcaattttt tttatgtcct gcacaggaaa atttcaggtt 180 atagatcggg gtgatggggg agatgaaatt tatttaaaca aacaagatgg tgtgagtttt 240 gagattccta aagtgtggga taaaaattat aagattatca cttctagaga taaaagatat 300 ggcaaaaagt taacttttaa aaaaaaggat aagaaatgca acgttatact tttagaaata 360 tggattttga atgaggaata ttggagtgaa tttaaagatg ttaggaagtt taaacttata 420 ggtaaaagcg aaaaaggcgt agtagtttat tcaagaggta aattagatag catattagaa 480 aataatggat tggacattat gcatcataaa gaagagaaaa agaaagatat agaaaaaatg 540 tacattaaag atgaagaaat tagcgataga atcaaaataa ttagaaatta ataaaaaaat 600 gaaaatagaa aaattcattt tactaaaaat ttatgtttac tttctataac aatctttgta 660 aactgtaaat actaatgtag tattttttag aaaataataa tctgttaaaa agtgtattta 720 ggaactaaaa atgaataaat ttataaaaac tatttacaat atctaaaata atgtatataa 780 tttttattaa atagattatt ttggtattaa gggggtggtt gaaagaataa acagaaaatt 840 gatataattc aataaataaa atctaaagag aaatatctaa gtaatacaca aatctaatat 900 taaaatcatt ttaatattaa gaatattttg ttaataggta aaggttaaaa ggcattctat 960 tattaaggtt aaaaggtatt aattattaag ggggattatc tatgaaaaaa aatattttaa 1020 agattcttat ggatagttat tctaaagaat ctaaaattca aactgtacgt agggttacga 1080 gtgtatcact tttagcggca tatcttacta tgaatacttc aagtttagtt ttagcaaaac 1140 caatagaaaa tactaatgat actagtataa aaaatgtgga gaaattaaga aatgctccaa 1200 atgaagagaa tagtaaaaag gtagaagata gtaaaaatga taaggtagaa catgtgaaaa 1260 atatagaaga ggcaaaggtt gagcaagttg cacccgaagt aaaatctaaa tcaactttaa 1320 gaagtgcttc t ata gcg aat act aat tct gag aaa tat gat ttt gag tat 1370 Ile Ala Asn Thr Asn Ser Glu Lys Tyr Asp Phe Glu Tyr 1 5 10 tta aat ggt ttg agc tat act gaa ctt aca aat tta att aaa aat ata 1418 Leu Asn Gly Leu Ser Tyr Thr Glu Leu Thr Asn Leu Ile Lys Asn Ile 15 20 25 aag tgg aat caa att aat ggt tta ttt aat tat agt aca ggt tct caa 1466 Lys Trp Asn Gln Ile Asn Gly Leu Phe Asn Tyr Ser Thr Gly Ser Gln 30 35 40 45 aag ttc ttt gga gat aaa aat cgt gta caa gct ata att aat gct tta 1514 Lys Phe Phe Gly Asp Lys Asn Arg Val Gln Ala Ile Ile Asn Ala Leu 50 55 60 caa gaa agt gga aga act tac act gca aat gat atg aag ggt ata gaa 1562 Gln Glu Ser Gly Arg Thr Tyr Thr Ala Asn Asp Met Lys Gly Ile Glu 65 70 75 act ttc act gag gtt tta aga gct ggt ttt tat tta ggg tac tat aat 1610 Thr Phe Thr Glu Val Leu Arg Ala Gly Phe Tyr Leu Gly Tyr Tyr Asn 80 85 90 gat ggt tta tct tat tta aat gat aga aac ttc caa gat aaa tgt ata 1658 Asp Gly Leu Ser Tyr Leu Asn Asp Arg Asn Phe Gln Asp Lys Cys Ile 95 100 105 cct gca atg att gca att caa aaa aat cct aac ttt aag cta gga act 1706 Pro Ala Met Ile Ala Ile Gln Lys Asn Pro Asn Phe Lys Leu Gly Thr 110 115 120 125 gca gtt caa gat gaa gtt ata act tct tta gga aaa cta ata gga aat 1754 Ala Val Gln Asp Glu Val Ile Thr Ser Leu Gly Lys Leu Ile Gly Asn 130 135 140 gct tct gct aat gct gaa gta gtt aat aat tgt gta cca gtt cta aaa 1802 Ala Ser Ala Asn Ala Glu Val Val Asn Asn Cys Val Pro Val Leu Lys 145 150 155 caa ttt aga gaa aac tta aat caa tat gct cct gat tac gtt aaa gga 1850 Gln Phe Arg Glu Asn Leu Asn Gln Tyr Ala Pro Asp Tyr Val Lys Gly 160 165 170 aca gct gta aat gaa tta att aaa ggt att gaa ttc gat ttt tct ggt 1898 Thr Ala Val Asn Glu Leu Ile Lys Gly Ile Glu Phe Asp Phe Ser Gly 175 180 185 gct gca tat gaa aaa gat gtt aag aca atg cct tgg tat gga aaa att 1946 Ala Ala Tyr Glu Lys Asp Val Lys Thr Met Pro Trp Tyr Gly Lys Ile 190 195 200 205 gat cca ttt ata aat gaa ctt aag gcc tta ggt cta tat gga aat ata 1994 Asp Pro Phe Ile Asn Glu Leu Lys Ala Leu Gly Leu Tyr Gly Asn Ile 210 215 220 aca agt gca act gag tgg gca tct gat gtt gga ata tac tat tta agt 2042 Thr Ser Ala Thr Glu Trp Ala Ser Asp Val Gly Ile Tyr Tyr Leu Ser 225 230 235 aaa ttc ggg ctt tac tca act aac cga aat gac ata gta cag tca ctt 2090 Lys Phe Gly Leu Tyr Ser Thr Asn Arg Asn Asp Ile Val Gln Ser Leu 240 245 250 gaa aag gct gta gat atg tat aag tat ggt aaa ata gcc ttt gta gca 2138 Glu Lys Ala Val Asp Met Tyr Lys Tyr Gly Lys Ile Ala Phe Val Ala 255 260 265 atg gag aga ata act tgg gat tat gat ggg att ggt tct aat ggt aaa 2186 Met Glu Arg Ile Thr Trp Asp Tyr Asp Gly Ile Gly Ser Asn Gly Lys 270 275 280 285 aag gtg gat cac gat aag ttc tta gat gat gct gaa aaa cat tat ctg 2234 Lys Val Asp His Asp Lys Phe Leu Asp Asp Ala Glu Lys His Tyr Leu 290 295 300 cca aag aca tat act ttt gat aat gga acc ttt att ata aga gca ggg 2282 Pro Lys Thr Tyr Thr Phe Asp Asn Gly Thr Phe Ile Ile Arg Ala Gly 305 310 315 gat aag gta tcc gaa gaa aaa ata aaa agg cta tat tgg gca tca aga 2330 Asp Lys Val Ser Glu Glu Lys Ile Lys Arg Leu Tyr Trp Ala Ser Arg 320 325 330 gaa gtg aag tct caa ttc cat aga gta gtt ggc aat gat aaa gct tta 2378 Glu Val Lys Ser Gln Phe His Arg Val Val Gly Asn Asp Lys Ala Leu 335 340 345 gag gtg gga aat gcc gat gat gtt tta act atg aaa ata ttt aat agc 2426 Glu Val Gly Asn Ala Asp Asp Val Leu Thr Met Lys Ile Phe Asn Ser 350 355 360 365 cca gaa gaa tat aaa ttt aat acc aat ata aat ggt gta agt act gat 2474 Pro Glu Glu Tyr Lys Phe Asn Thr Asn Ile Asn Gly Val Ser Thr Asp 370 375 380 aat ggt ggt cta tat ata gaa cca aga ggg act ttc tac act tat gag 2522 Asn Gly Gly Leu Tyr Ile Glu Pro Arg Gly Thr Phe Tyr Thr Tyr Glu 385 390 395 aga aca cct caa caa agt ata ttt agt ctt gaa gaa ttg ttt aga cat 2570 Arg Thr Pro Gln Gln Ser Ile Phe Ser Leu Glu Glu Leu Phe Arg His 400 405 410 gaa tat act cac tat tta caa gcg aga tat ctt gta gat ggt tta tgg 2618 Glu Tyr Thr His Tyr Leu Gln Ala Arg Tyr Leu Val Asp Gly Leu Trp 415 420 425 ggg caa ggt cca ttt tat gaa aaa aat aga tta act tgg ttt gat gaa 2666 Gly Gln Gly Pro Phe Tyr Glu Lys Asn Arg Leu Thr Trp Phe Asp Glu 430 435 440 445 ggt aca gct gaa ttc ttt gca gga tct acc cgt aca tct ggt gtt tta 2714 Gly Thr Ala Glu Phe Phe Ala Gly Ser Thr Arg Thr Ser Gly Val Leu 450 455 460 cca aga aaa tca ata tta gga tat ttg gct aag gat aaa gta gat cat 2762 Pro Arg Lys Ser Ile Leu Gly Tyr Leu Ala Lys Asp Lys Val Asp His 465 470 475 aga tac tca tta aag aag act ctt aat tca ggg tat gat gac agt gat 2810 Arg Tyr Ser Leu Lys Lys Thr Leu Asn Ser Gly Tyr Asp Asp Ser Asp 480 485 490 tgg atg ttc tat aat tat gga ttt gca gtt gca cat tac cta tat gaa 2858 Trp Met Phe Tyr Asn Tyr Gly Phe Ala Val Ala His Tyr Leu Tyr Glu 495 500 505 aaa gat atg cct aca ttt att aag atg aat aaa gct ata ttg aat aca 2906 Lys Asp Met Pro Thr Phe Ile Lys Met Asn Lys Ala Ile Leu Asn Thr 510 515 520 525 gat gtg aaa tct tat gat gaa ata ata aaa aaa tta agt gat gat gca 2954 Asp Val Lys Ser Tyr Asp Glu Ile Ile Lys Lys Leu Ser Asp Asp Ala 530 535 540 aat aaa aat aca gaa tat caa aac cat att caa gag tta gta gat aaa 3002 Asn Lys Asn Thr Glu Tyr Gln Asn His Ile Gln Glu Leu Val Asp Lys 545 550 555 tat caa gga gct gga cta cct cta gta tca gat gat tac tta aaa gat 3050 Tyr Gln Gly Ala Gly Leu Pro Leu Val Ser Asp Asp Tyr Leu Lys Asp 560 565 570 cat gga tat aag aaa gca tct gaa gta tat tct gaa att tca aaa gct 3098 His Gly Tyr Lys Lys Ala Ser Glu Val Tyr Ser Glu Ile Ser Lys Ala 575 580 585 gct tct ctt aca aac act agt gta aca gca gaa aaa tct caa tac ttt 3146 Ala Ser Leu Thr Asn Thr Ser Val Thr Ala Glu Lys Ser Gln Tyr Phe 590 595 600 605 aac aca ttc act tta aga gga act tat aca ggt gaa act tct aaa ggt 3194 Asn Thr Phe Thr Leu Arg Gly Thr Tyr Thr Gly Glu Thr Ser Lys Gly 610 615 620 gaa ttt aaa gat tgg gat gaa atg agt aaa aaa tta gat gga act ttg 3242 Glu Phe Lys Asp Trp Asp Glu Met Ser Lys Lys Leu Asp Gly Thr Leu 625 630 635 gag tcc ctt gct aaa aat tct tgg agt gga tac aaa acc tta aca gca 3290 Glu Ser Leu Ala Lys Asn Ser Trp Ser Gly Tyr Lys Thr Leu Thr Ala 640 645 650 tac ttt acg aat tat aga gtt aca agc gat aat aaa gtt caa tat gat 3338 Tyr Phe Thr Asn Tyr Arg Val Thr Ser Asp Asn Lys Val Gln Tyr Asp 655 660 665 gta gtt ttc cat ggg gtt tta aca gat aat ggg gat att agt aac aat 3386 Val Val Phe His Gly Val Leu Thr Asp Asn Gly Asp Ile Ser Asn Asn 670 675 680 685 aag gct cca ata gca aag gta act gga cca agc act ggt gct gta gga 3434 Lys Ala Pro Ile Ala Lys Val Thr Gly Pro Ser Thr Gly Ala Val Gly 690 695 700 aga aat att gaa ttt agt gga aaa gat agt aaa gat gaa gat ggt aaa 3482 Arg Asn Ile Glu Phe Ser Gly Lys Asp Ser Lys Asp Glu Asp Gly Lys 705 710 715 ata gta tca tat gat tgg gat ttt ggc gat ggt gca act agt aga ggc 3530 Ile Val Ser Tyr Asp Trp Asp Phe Gly Asp Gly Ala Thr Ser Arg Gly 720 725 730 aaa aat tca gta cat gct tac aaa aaa gca gga aca tat aat gtt aca 3578 Lys Asn Ser Val His Ala Tyr Lys Lys Ala Gly Thr Tyr Asn Val Thr 735 740 745 tta aaa gta act gac gat aag ggt gca aca gct aca gaa agc ttt act 3626 Leu Lys Val Thr Asp Asp Lys Gly Ala Thr Ala Thr Glu Ser Phe Thr 750 755 760 765 ata gaa ata aag aac gaa gat aca aca aca cct ata act aaa gaa atg 3674 Ile Glu Ile Lys Asn Glu Asp Thr Thr Thr Pro Ile Thr Lys Glu Met 770 775 780 gaa cct aat gat gat ata aaa gag gct aat ggt cca ata gtt gaa ggt 3722 Glu Pro Asn Asp Asp Ile Lys Glu Ala Asn Gly Pro Ile Val Glu Gly 785 790 795 gtt act gta aaa ggt gat tta aat ggt tct gat gat gct gat acc ttc 3770 Val Thr Val Lys Gly Asp Leu Asn Gly Ser Asp Asp Ala Asp Thr Phe 800 805 810 tat ttt gat gta aaa gaa gat ggt gat gtt aca att gaa ctt cct tat 3818 Tyr Phe Asp Val Lys Glu Asp Gly Asp Val Thr Ile Glu Leu Pro Tyr 815 820 825 tca ggg tca tct aat ttc aca tgg tta gtt tat aaa gag gga gac gat 3866 Ser Gly Ser Ser Asn Phe Thr Trp Leu Val Tyr Lys Glu Gly Asp Asp 830 835 840 845 caa aat cat att gca agt ggt ata gat aag aat aac tca aaa gtt gga 3914 Gln Asn His Ile Ala Ser Gly Ile Asp Lys Asn Asn Ser Lys Val Gly 850 855 860 aca ttt aaa gct aca aaa gga aga cat tat gtg ttt ata tat aaa cac 3962 Thr Phe Lys Ala Thr Lys Gly Arg His Tyr Val Phe Ile Tyr Lys His 865 870 875 gat tct gct tca aat ata tcc tat tct tta aac ata aaa gga tta ggt 4010 Asp Ser Ala Ser Asn Ile Ser Tyr Ser Leu Asn Ile Lys Gly Leu Gly 880 885 890 aac gag aaa ttg aag gaa aaa gaa aat aat gat tct tct gat aaa gct 4058 Asn Glu Lys Leu Lys Glu Lys Glu Asn Asn Asp Ser Ser Asp Lys Ala 895 900 905 aca gtt ata cca aat ttc aat acc act atg caa ggt tca ctt tta ggt 4106 Thr Val Ile Pro Asn Phe Asn Thr Thr Met Gln Gly Ser Leu Leu Gly 910 915 920 925 gat gat tca aga gat tat tat tct ttt gag gtt aag gaa gaa ggc gaa 4154 Asp Asp Ser Arg Asp Tyr Tyr Ser Phe Glu Val Lys Glu Glu Gly Glu 930 935 940 gtt aat ata gaa cta gat aaa aag gat gaa ttt ggt gta aca tgg aca 4202 Val Asn Ile Glu Leu Asp Lys Lys Asp Glu Phe Gly Val Thr Trp Thr 945 950 955 cta cat cca gag tca aat att aat gac aga ata act tac gga caa gtt 4250 Leu His Pro Glu Ser Asn Ile Asn Asp Arg Ile Thr Tyr Gly Gln Val 960 965 970 gat ggt aat aag gta tct aat aaa gtt aaa tta aga cca gga aaa tat 4298 Asp Gly Asn Lys Val Ser Asn Lys Val Lys Leu Arg Pro Gly Lys Tyr 975 980 985 tat cta ctt gtt tat aaa tac tca gga tca gga aac tat gag tta agg 4346 Tyr Leu Leu Val Tyr Lys Tyr Ser Gly Ser Gly Asn Tyr Glu Leu Arg 990 995 1000 1005 gta aat aaa taa 4358 Val Asn Lys 2 1008 PRT Clostridium histolyticum 2 Ile Ala Asn Thr Asn Ser Glu Lys Tyr Asp Phe Glu Tyr Leu Asn Gly 1 5 10 15 Leu Ser Tyr Thr Glu Leu Thr Asn Leu Ile Lys Asn Ile Lys Trp Asn 20 25 30 Gln Ile Asn Gly Leu Phe Asn Tyr Ser Thr Gly Ser Gln Lys Phe Phe 35 40 45 Gly Asp Lys Asn Arg Val Gln Ala Ile Ile Asn Ala Leu Gln Glu Ser 50 55 60 Gly Arg Thr Tyr Thr Ala Asn Asp Met Lys Gly Ile Glu Thr Phe Thr 65 70 75 80 Glu Val Leu Arg Ala Gly Phe Tyr Leu Gly Tyr Tyr Asn Asp Gly Leu 85 90 95 Ser Tyr Leu Asn Asp Arg Asn Phe Gln Asp Lys Cys Ile Pro Ala Met 100 105 110 Ile Ala Ile Gln Lys Asn Pro Asn Phe Lys Leu Gly Thr Ala Val Gln 115 120 125 Asp Glu Val Ile Thr Ser Leu Gly Lys Leu Ile Gly Asn Ala Ser Ala 130 135 140 Asn Ala Glu Val Val Asn Asn Cys Val Pro Val Leu Lys Gln Phe Arg 145 150 155 160 Glu Asn Leu Asn Gln Tyr Ala Pro Asp Tyr Val Lys Gly Thr Ala Val 165 170 175 Asn Glu Leu Ile Lys Gly Ile Glu Phe Asp Phe Ser Gly Ala Ala Tyr 180 185 190 Glu Lys Asp Val Lys Thr Met Pro Trp Tyr Gly Lys Ile Asp Pro Phe 195 200 205 Ile Asn Glu Leu Lys Ala Leu Gly Leu Tyr Gly Asn Ile Thr Ser Ala 210 215 220 Thr Glu Trp Ala Ser Asp Val Gly Ile Tyr Tyr Leu Ser Lys Phe Gly 225 230 235 240 Leu Tyr Ser Thr Asn Arg Asn Asp Ile Val Gln Ser Leu Glu Lys Ala 245 250 255 Val Asp Met Tyr Lys Tyr Gly Lys Ile Ala Phe Val Ala Met Glu Arg 260 265 270 Ile Thr Trp Asp Tyr Asp Gly Ile Gly Ser Asn Gly Lys Lys Val Asp 275 280 285 His Asp Lys Phe Leu Asp Asp Ala Glu Lys His Tyr Leu Pro Lys Thr 290 295 300 Tyr Thr Phe Asp Asn Gly Thr Phe Ile Ile Arg Ala Gly Asp Lys Val 305 310 315 320 Ser Glu Glu Lys Ile Lys Arg Leu Tyr Trp Ala Ser Arg Glu Val Lys 325 330 335 Ser Gln Phe His Arg Val Val Gly Asn Asp Lys Ala Leu Glu Val Gly 340 345 350 Asn Ala Asp Asp Val Leu Thr Met Lys Ile Phe Asn Ser Pro Glu Glu 355 360 365 Tyr Lys Phe Asn Thr Asn Ile Asn Gly Val Ser Thr Asp Asn Gly Gly 370 375 380 Leu Tyr Ile Glu Pro Arg Gly Thr Phe Tyr Thr Tyr Glu Arg Thr Pro 385 390 395 400 Gln Gln Ser Ile Phe Ser Leu Glu Glu Leu Phe Arg His Glu Tyr Thr 405 410 415 His Tyr Leu Gln Ala Arg Tyr Leu Val Asp Gly Leu Trp Gly Gln Gly 420 425 430 Pro Phe Tyr Glu Lys Asn Arg Leu Thr Trp Phe Asp Glu Gly Thr Ala 435 440 445 Glu Phe Phe Ala Gly Ser Thr Arg Thr Ser Gly Val Leu Pro Arg Lys 450 455 460 Ser Ile Leu Gly Tyr Leu Ala Lys Asp Lys Val Asp His Arg Tyr Ser 465 470 475 480 Leu Lys Lys Thr Leu Asn Ser Gly Tyr Asp Asp Ser Asp Trp Met Phe 485 490 495 Tyr Asn Tyr Gly Phe Ala Val Ala His Tyr Leu Tyr Glu Lys Asp Met 500 505 510 Pro Thr Phe Ile Lys Met Asn Lys Ala Ile Leu Asn Thr Asp Val Lys 515 520 525 Ser Tyr Asp Glu Ile Ile Lys Lys Leu Ser Asp Asp Ala Asn Lys Asn 530 535 540 Thr Glu Tyr Gln Asn His Ile Gln Glu Leu Val Asp Lys Tyr Gln Gly 545 550 555 560 Ala Gly Leu Pro Leu Val Ser Asp Asp Tyr Leu Lys Asp His Gly Tyr 565 570 575 Lys Lys Ala Ser Glu Val Tyr Ser Glu Ile Ser Lys Ala Ala Ser Leu 580 585 590 Thr Asn Thr Ser Val Thr Ala Glu Lys Ser Gln Tyr Phe Asn Thr Phe 595 600 605 Thr Leu Arg Gly Thr Tyr Thr Gly Glu Thr Ser Lys Gly Glu Phe Lys 610 615 620 Asp Trp Asp Glu Met Ser Lys Lys Leu Asp Gly Thr Leu Glu Ser Leu 625 630 635 640 Ala Lys Asn Ser Trp Ser Gly Tyr Lys Thr Leu Thr Ala Tyr Phe Thr 645 650 655 Asn Tyr Arg Val Thr Ser Asp Asn Lys Val Gln Tyr Asp Val Val Phe 660 665 670 His Gly Val Leu Thr Asp Asn Gly Asp Ile Ser Asn Asn Lys Ala Pro 675 680 685 Ile Ala Lys Val Thr Gly Pro Ser Thr Gly Ala Val Gly Arg Asn Ile 690 695 700 Glu Phe Ser Gly Lys Asp Ser Lys Asp Glu Asp Gly Lys Ile Val Ser 705 710 715 720 Tyr Asp Trp Asp Phe Gly Asp Gly Ala Thr Ser Arg Gly Lys Asn Ser 725 730 735 Val His Ala Tyr Lys Lys Ala Gly Thr Tyr Asn Val Thr Leu Lys Val 740 745 750 Thr Asp Asp Lys Gly Ala Thr Ala Thr Glu Ser Phe Thr Ile Glu Ile 755 760 765 Lys Asn Glu Asp Thr Thr Thr Pro Ile Thr Lys Glu Met Glu Pro Asn 770 775 780 Asp Asp Ile Lys Glu Ala Asn Gly Pro Ile Val Glu Gly Val Thr Val 785 790 795 800 Lys Gly Asp Leu Asn Gly Ser Asp Asp Ala Asp Thr Phe Tyr Phe Asp 805 810 815 Val Lys Glu Asp Gly Asp Val Thr Ile Glu Leu Pro Tyr Ser Gly Ser 820 825 830 Ser Asn Phe Thr Trp Leu Val Tyr Lys Glu Gly Asp Asp Gln Asn His 835 840 845 Ile Ala Ser Gly Ile Asp Lys Asn Asn Ser Lys Val Gly Thr Phe Lys 850 855 860 Ala Thr Lys Gly Arg His Tyr Val Phe Ile Tyr Lys His Asp Ser Ala 865 870 875 880 Ser Asn Ile Ser Tyr Ser Leu Asn Ile Lys Gly Leu Gly Asn Glu Lys 885 890 895 Leu Lys Glu Lys Glu Asn Asn Asp Ser Ser Asp Lys Ala Thr Val Ile 900 905 910 Pro Asn Phe Asn Thr Thr Met Gln Gly Ser Leu Leu Gly Asp Asp Ser 915 920 925 Arg Asp Tyr Tyr Ser Phe Glu Val Lys Glu Glu Gly Glu Val Asn Ile 930 935 940 Glu Leu Asp Lys Lys Asp Glu Phe Gly Val Thr Trp Thr Leu His Pro 945 950 955 960 Glu Ser Asn Ile Asn Asp Arg Ile Thr Tyr Gly Gln Val Asp Gly Asn 965 970 975 Lys Val Ser Asn Lys Val Lys Leu Arg Pro Gly Lys Tyr Tyr Leu Leu 980 985 990 Val Tyr Lys Tyr Ser Gly Ser Gly Asn Tyr Glu Leu Arg Val Asn Lys 995 1000 1005 3 110 PRT Clostridium histolyticum 3 Met Lys Lys Asn Ile Leu Lys Ile Leu Met Asp Ser Tyr Ser Lys Glu 1 5 10 15 Ser Lys Ile Gln Thr Val Arg Arg Val Thr Ser Val Ser Leu Leu Ala 20 25 30 Ala Tyr Leu Thr Met Asn Thr Ser Ser Leu Val Leu Ala Lys Pro Ile 35 40 45 Glu Asn Thr Asn Asp Thr Ser Ile Lys Asn Val Glu Lys Leu Arg Asn 50 55 60 Ala Pro Asn Glu Glu Asn Ser Lys Lys Val Glu Asp Ser Lys Asn Asp 65 70 75 80 Lys Val Glu His Val Lys Asn Ile Glu Glu Ala Lys Val Glu Gln Val 85 90 95 Ala Pro Glu Val Lys Ser Lys Ser Thr Leu Arg Ser Ala Ser 100 105 110 4 7 PRT Clostridium histolyticum 4 Phe Asn Ser Pro Glu Glu Tyr 1 5 5 7 PRT Clostridium histolyticum 5 Glu Asp Gly Asp Val Thr Ile 1 5 6 21 DNA Artificial sequence misc_feature (9)..(9) can be any nucleotide 6 ttyaaywsnc cngargarta y 21 7 21 DNA Artificial sequence misc_feature (10)..(10) can be any nucleotide 7 rtaytcytcn ggnswrttra a 21 8 21 DNA Artificial sequence misc_feature (9)..(9) can be any nucleotide 8 gargayggng aygtnacnat t 21 9 21 DNA Artificial sequence misc_feature (4)..(4) can be any nucleotide 9 datngtnacr tcnccrtcyt c 21 10 7 PRT Clostridium histolyticum 10 Asp Trp Asp Glu Met Ser Lys 1 5 11 18 PRT Clostridium histolyticum 11 Val Thr Gly Pro Ser Thr Gly Ala Val Gly Arg Asn Ile Glu Phe Ser 1 5 10 15 Gly Lys 12 14 PRT Clostridium histolyticum 12 Asn Thr Glu Tyr Gln Asn His Ile Gln Glu Leu Val Asp Lys 1 5 10 13 22 PRT Clostridium histolyticum 13 Glu Asp Gly Asp Val Thr Ile Glu Leu Pro Tyr Ser Gly Ser Ser Asn 1 5 10 15 Phe Thr Trp Leu Val Tyr 20 14 15 PRT Clostridium histolyticum 14 Gln Phe Arg Glu Asn Leu Asn Gln Tyr Ala Pro Asp Tyr Val Lys 1 5 10 15 15 19 DNA Clostridium histolyticum 15 agacaatgcc ttggtatgg 19 16 21 DNA Clostridium histolyticum 16 gtgaaagttt ctataccctt c 21 17 20 DNA Clostridium histolyticum 17 gtacaggttc tcaaaagttc 20 18 20 DNA Clostridium histolyticum 18 gttcctttaa cgtaatcagg 20 19 8 PRT Clostridium histolyticum 19 Ile Ala Asn Thr Asn Ser Glu Lys 1 5 20 18 PRT Clostridium histolyticum 20 Met Thr Met Ile Thr Asn Ser Arg Ala Met Lys Lys Asn Ile Leu Lys 1 5 10 15 Ile Leu 21 18 PRT Clostridium histolyticum 21 Met Thr Met Ile Thr Asn Ser Arg Ala Met Asp Ser Tyr Ser Lys Glu 1 5 10 15 Ser Lys 22 18 PRT Clostridium histolyticum 22 Met Thr Met Ile Thr Asn Ser Arg Ala Met Lys Asn Ile Glu Glu Ala 1 5 10 15 Lys Val 23 42 DNA Clostridium histolyticum 23 ttcccaattg cccgggctat gaaaaatata gaagaggcaa ag 42 24 8 PRT Clostridium histolyticum 24 Ala Tyr Leu Thr Met Asn Thr Ser 1 5 

What is claimed is:
 1. A polypeptide comprising the amino acid sequence SEQ ID NO:
 2. 2. The polypeptide of claim 1 wherein the polypeptide is N-terminally extended by one or more amino acids of the sequence SEQ ID NO:
 3. 3. A polypeptide encoded by the sequence SEQ ID NO: 1, wherein said coding begins at nucleotide 1002, 1029, 1110, 1176 or 1254 of SEQ ID NO:
 1. 4. A method useful for the isolation of cells from mammalian tissue and human tissue, said method comprising contacting the tissue with the polypeptide of claim
 1. 5. A method useful for the isolation of cells from mammalian tissue and human tissue, said method comprising contacting the tissue with the polypeptide of claim
 2. 6. A method useful for the isolation of cells from mammalian tissue and human tissue, said method comprising contacting the tissue with the polypeptide of claim
 3. 